Wi-Fi (sometimes written Wi-fi, WiFi, Wifi, wifi) is a trademark for set of product compatibility standards for wireless local area networks (WLANs). Wi-Fi, short for "Wireless Fidelity", was intended to allow mobile devices, such as laptop computers and personal digital assistants (PDAs) to connect to local area networks, but is now often used for Internet access and wireless VoIP phones. Desktop computers can use Wi-Fi too, allowing offices to be networked without expensive wiring. Many computers are sold today with Wi-Fi built-in, others require adding a Wi-Fi network card. Other devices, such as digital cameras, are sometimes equipped with Wi-Fi.

A person with a Wi-Fi-enabled device can connect to a local area network when near one of the network's access points. The connection is made by radio signals; there is no need to plug the device into the network. If the local area network is connected to the Internet, the Wi-Fi device can have Internet access as well. The geographical region covered by one or several access points is called a hotspot. The range of an access point varies. The access point built into a typical Wi-Fi home router might have a range of 45 m (150 ft) indoors and 90 m (300 ft) outdoors.